Three-point hitch for utility vehicle

ABSTRACT

A utility vehicle includes front and rear wheel assemblies, a frame supported on the front and rear wheel assemblies, and an operator compartment supported on the frame and having operator controls. The frame includes a central, tubular frame member having a front end portion and a rear end portion. An engine is supported on the frame for providing power to the front and rear wheel assemblies. A cooling assembly mounted above the engine. An attachment arm is attached to the front portion of the frame and a rear interface mount is rigidly attached to the rear portion of the frame.

RELATED APPLICATIONS

This application claims the benefit of provisional U.S. patentapplication Ser. No. 60/821,732 filed on Aug. 8, 2006, the entiredisclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a self-propelled work vehicle.

SUMMARY

In one embodiment, the invention provides a utility vehicle including aframe, front and rear wheel assemblies supporting the frame and anoperator compartment supported on the frame and having operatorcontrols. An engine is supported on the frame for providing power to thefront and rear wheel assemblies, and a cooling assembly is mounted abovethe engine. The utility vehicle also includes an attachment arm attachedto a front portion of the frame and a rear interface mount rigidlyattached to a rear portion of the frame. The rear interface mount has aplurality of interface apertures adapted for accommodating attachment ofone or more of a plurality of work mechanisms to the rear interfacemount. The rear interface mount can accommodate the interfaces of workmechanisms in which the interface of a first work mechanism is differentfrom an interface of a second work mechanism. The frame includes acentral, tubular frame member having a front end portion and a rear endportion.

In another embodiment the invention provides a three-point hitchassembly for a utility vehicle including an upper link, a pair of liftarms, a pair of lower links coupled to the lift arms, a rock shaftconnecting the lift arms, a hydraulic cylinder and an actuator armcoupling the hydraulic cylinder to the rock shaft for transferring alifting force from the hydraulic cylinder to the rock shaft. Thethree-point hitch assembly further includes a float mechanism forinhibiting a transfer of force from the rock shaft to the hydrauliccylinder. The float mechanism includes a float block fixed to the rockshaft. The float mechanism includes a slot in one of the float block andthe actuator arm and a protrusion in the other of the float block andthe actuator arm. The protrusion is rotatable within the slot to permitrotation of the rock shaft relative to the actuator arm.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a utility vehicle according toan embodiment of the invention.

FIG. 2 illustrates a right side view of the utility vehicle of FIG. 1.

FIG. 3 illustrates a perspective view of a portion of the frameaccording to an embodiment of the invention.

FIG. 4 illustrates another perspective view of the frame of FIG. 3.

FIG. 5 illustrates a perspective view of the utility vehicle of FIG. 1with the rear cover removed.

FIG. 6 illustrates a side view of the utility vehicle of FIG. 5.

FIG. 7 illustrates an exploded view of the cooling assembly according toan embodiment of the invention.

FIG. 8 illustrates a perspective view of the rear cover according to anembodiment of the invention.

FIG. 9 illustrates a perspective view of the utility vehicle of FIG. 1including a rear arm assembly having a tool interface plate attached tothe rear interface mount.

FIG. 10 illustrates a perspective view of the utility vehicle of FIG. 1including a three point hitch assembly attached to the rear interfacemount.

FIG. 11 illustrates a perspective view of the utility vehicle of FIG. 1including a box attached to the rear interface mount.

FIG. 12 illustrates an exploded perspective view of the three-pointhitch assembly of FIG. 10.

FIG. 13 illustrates a cut-away side view of the three-point hitchassembly of FIG. 12 taken along line A-A.

FIG. 14 illustrates the three-point hitch assembly of FIG. 13 with thelower links raised.

FIG. 15 illustrates a sectional view of a three-point hitch assemblyaccording to another embodiment of the invention.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings.

FIG. 1 illustrates a utility vehicle 100 according to an embodiment ofthe invention. The utility vehicle 100 includes a frame 103 supportedwith front and rear wheel assemblies 106, 109. The frame 103 is attachedto a cab 112 that forms an operator compartment 115. The utility vehicle100 includes an engine 116 (see FIG. 5) for driving operation of thevehicle 100. The engine 116 can be an internal combustion engine, butcan also be a hydraulic engine, a steam engine, etc. The engine 116 isdisposed between the cab 112 and the rear wheel assembly 109 and isattached to the frame 103. The utility vehicle 100 further includes anattachment arm assembly 118 positioned in front of the cab 112 that isattached to a front portion of the frame 103. The utility vehicle 100also includes a rear cover 121 and a rear interface mount 124.

FIG. 2 is a right side view of the utility vehicle 100. The frame 103 isa rigid frame assembly that lacks frame articulation between the frontand rear wheel assemblies 106, 109. FIGS. 3 and 4 show a portion of theframe 103. The frame 103 includes an engine support portion 127, amiddle portion 130 for supporting the cab 112, and an attachment armsupport portion 133. The middle portion 130 is adapted to provide astable mount for the cab 112 and can be adapted to accommodate an enginemounted longitudinally or transversely with respect to the frame 103.

The attachment arm support portion 133 includes a central, tubularmember 136 extending transversely underneath the cab 112. The tubularmember 136 can have a rectangular cross-sectional shape. A front portionof the beam 136 forms the attachment arm support portion 133 while arear portion of the beam 136 forms the middle portion 130 and the enginesupport portion 127. The attachment arm support portion 133 and theengine support portion 127 can be integrally formed with the tubularmember 136 or can be welded or otherwise rigidly attached to the tubularmember 136. The attachment arm support portion 133 is strengthened toresist bending or twisting from loads carried with the attachment armassembly 118. A brace member 134 is attached to the tubular member 136and provides additional support for the attachment arm support portion133. The rear interface mount 124 is rigidly attached to a rear portionof the tubular member 136. The frame 103 further includes various frameinterface apertures 135 on the attachment arm support portion 133, themiddle portion 130 and the engine support portion 127. The frameinterface apertures 135 can have various diameters for receiving boltsor other connecting members for mounting the operator cab 112, engine116, front and rear wheel assemblies 106, 109, etc. to the frame 103.The interface apertures 135 are arranged to facilitate attachingcomponents having varying configurations and different types ofcomponents. In this manner, the frame 103 is capable of providing asupport platform for utility vehicles having varying configurations. Theframe 103 further includes secondary frame support members 137 ofvarious configurations for facilitating attachment to different utilityvehicle components. The secondary frame support members 137 can beintegrally formed, welded, or otherwise fixed to the tubular framemember 136.

Returning to FIG. 2, the attachment arm assembly 118 is mounted to theattachment arm support portion 133 of the frame 103. The attachment armassembly 118 is coupled to the frame 103 such that the attachment armassembly 118 can be moved relative to the frame 103. Movement of theattachment arm assembly 118 can be controlled through the operatorcontrols 139 located in the operator compartment 115 and can be poweredthrough the use of hydraulic actuators or other types of electrical ormechanical actuators that receive power from the engine.

A remote or working end 142 of the attachment arm assembly 118 can beconnected to a front arm interface plate 145 that provides an interfacefor attaching to various tools. Such tools can include, for example,blades, buckets, grapples, brooms, augers, pallet forks, etc. (noneshown). The front arm interface plate 145 can provide an interface as isdisclosed in U.S. Pat. No. 5,562,397, the entire contents of which arehereby incorporated herein by reference.

FIG. 5 shows the engine 116, which can provide power to either or bothof the front and rear wheel assemblies 106, 109 to move the utilityvehicle 100. The engine 116 is connected to one or both of the front andrear wheel assemblies 106, 109 with mechanical drives, hydraulic motorsor other suitable devices for power transmission. The front and rearwheel assemblies 106, 109 can include suspension systems coupled to theframe 103. A steering linkage can be coupled to either or both of thefront and rear wheel assemblies 106, 109. Controls 139 for operation ofthe utility vehicle 100 are located in the operator compartment 115.

The utility vehicle 100 further includes a cooling assembly 148 (seeFIGS. 5-8) that is covered by the rear cover 121. FIGS. 1 and 8 show therear cover 121, which includes a radiator screen 151 for permitting airflow therethrough. Although the radiator screen 151 is illustrated ashaving a plurality of linear slats, it should be understood that theradiator screen 151 can be configured in various ways as long as theradiator screen 151 can be used as an exhaust for the cooling assembly148. The rear cover 121 also includes a pair of containers 154 formedintegrally with the rear cover 121, a pair of handles 157 and a pair oftail lights 160. The handles 157 are adapted for use in at leastpartially removing or lifting the rear cover 121 to access thecomponents located beneath, such as the cooling assembly 148 and/or theengine. The rear cover 121 can be fully detachable from the utilityvehicle 100, or can be movably attached to the utility vehicle 100 so asto be pivotable or otherwise movable from a closed, coveringorientation, as illustrated in FIG. 1, to an open, uncovered orientation(not shown) without being fully detached from the utility vehicle 100.The rear cover 121 can be lifted or otherwise moved away from theutility vehicle 100 at a front, rear or side portion.

In the illustrated embodiment, the radiator screen 151 is integral withthe containers 154. In other embodiments, the rear cover 121 includesone or more cover portions that can be coupled to one another orindependently mounted to the utility vehicle 100. For example, a centerportion of the rear cover 121 can be separate from side portions toallow the radiator screen 151 to be lifted for access underneath withoutdisturbing the containers 154.

In the illustrated embodiment, the radiator screen 151 is approximatelycentered on the rear cover 121 so that one of the pair of containers 154is positioned on each side. In other embodiments, the radiator screen151 can be closer to one side of the rear cover 121 and both or all ofthe containers 154 can be on the same side of the radiator screen 151.

The containers 154 can be utilized to carry various objects. Forexample, the containers 154 can carry various work tools, devices andsupplies for various kinds of work applications. The containers 154 canhave various dimensions and inner geometry. For example, the containers154 can be shaped to carry a five gallon bucket, a tool box, etc.

FIGS. 5 and 6 illustrate the utility vehicle 100 with the rear 121 coverremoved to illustrate the engine 116 and the cooling assembly 148. Thecooling assembly 148 is positioned above the engine and includes aradiator 163, a hydraulic oil cooler 166 and a hydraulic fan assembly169. By positioning the cooling assembly 148 at least partially abovethe engine 116, the utility vehicle 100 can be compact and stable.

FIG. 7 shows the cooling assembly 148. The radiator 163 includes coolingelements and is adapted to cool engine coolant that is continuouslycirculated through the engine 116. As illustrated in FIGS. 3 and 4, theradiator 163 is oriented at an angle from a horizontal axis of the frame103 or the ground to exit exhaust flow. In general, this angle isapproximately an acute angle. However, in other embodiments, theradiator 163 can be substantially parallel with the horizontal axis ofthe frame 103 or the ground to provide the rear portion of the utilityvehicle 100 with a lower profile. In still other embodiments, theradiator 163 can be arranged along a substantially vertical axis. Such aconfiguration could increase the usable space for the containers 154 orother features of the rear cover 121.

The hydraulic fan assembly 169 includes a cooling fan 172 surrounded bya fan shroud 175 that is located between the engine 116 and the radiator163. The cooling fan 172 is powered by a hydraulic fan motor 178. Thecooling fan 172 draws air from outside of the utility vehicle 100through the radiator screen 151 and across the engine to provideadditional cooling. Air drawn in by the cooling fan 172 can also be usedto cool oil and other fluids. By providing the cooling assembly 148 onan upper portion or an upward facing surface of the utility vehicle 100,dust and other debris that can be kicked up by the front and rear wheelassemblies 106, 109 is less likely to be drawn into the cooling assembly148 through the radiator screen 151. This can reduce wear on the coolingassembly 148 and help to maintain the cooling efficiency of the coolingassembly 148.

The cooling assembly 148 is pre-assembled into a modular unit that isthen mounted to the utility vehicle. A pair of opposed mounting brackets170 including cooling assembly mounting portions 170 a and vehiclemounting portions 170 b are provided for mounting the cooling assembly148 to the utility vehicle 100. The radiator 163, the hydraulic oilcooler 166 and the shroud 175 are mounted to the cooling assemblymounting portions 170 a to form a first sub-assembly. The hydraulic fanmotor 178 and the fan 172 are mounted to a lower mounting bracket 177 toform a second sub-assembly. The second sub-assembly is assembled withthe first sub-assembly to form a unit. The unit is installed to theutility vehicle 100 by mounting the vehicle mounting portions 170 b tothe utility vehicle 100.

Returning to FIG. 1, the rear interface mount 124 is integrally formed,welded or otherwise rigidly mounted to the frame 103 of the utilityvehicle 100, thereby permitting the rear interface mount 124 to carryheavy loads. The rear interface mount 124 is adapted to releasablyattach various types of work mechanisms or attachments to the utilityvehicle 100 for use in a variety of work applications. The rearinterface mount 124 provides versatility in attaching different types ofattachments by including a plurality of interface apertures 180. Therear interface mount 124 includes a front mount portion 183 and a rearmount portion 186 spaced apart from one another. A pair of side mountportions 189 join the front and rear mount portions 183, 186 to form agenerally box-shaped configuration. Lateral mount portions 192 aremounted to the frame 103 on each side of the side mount portions 189.

The rear interface mount 124 includes a plurality of interface apertures180 having various diameters and relative positions. The interfaceapertures 180 can receive bolts or other attachment mechanisms (notshown) extending horizontally, vertically, longitudinally (i.e., throughinterface apertures 180 in the front and/or rear mount portions) and/orlaterally (i.e., extending through the side mount portions 189). Variouscombinations of interface apertures 180 can be used to mount aparticular work mechanism to the rear interface mount 124. Thus, whilethe front attachment plate 145 can provide for releasably attaching avariety of attachments having a standardized interface while the rearinterface mount 124 can receive a variety of work mechanisms havingvarying interfaces.

As illustrated in FIG. 5, the rear interface mount 124 can attach a workmechanism such as a towing hook 195 using a portion of the plurality ofthe interface apertures. In addition, the rear interface mount 124 canattach a hitch receiver (not shown). However, the versatility of therear interface mount 124 permits more complicated work mechanisms to beattached to the utility vehicle 100. Some of these more complicated workmechanisms are illustrated in FIGS. 10-12.

FIG. 9 shows a rear arm assembly 197 mounted to the rear interface mount124. The rear arm assembly 197 is removably attached to the rearinterface mount 124 with a plurality of bolts. Like the attachment armassembly 118 which is supported on the front of the utility vehicle 100,the remote end of the rear arm assembly 197 can be connected to a toolinterface plate 198 that provides an interface plate for attaching tovarious tool (not shown). Such tools can include blades, buckets,grapples, brooms, augers, pallet forks, etc. Movement of the rear armassembly 197 is effected through the use of hydraulic or other types ofmechanical or electrical actuators 199, such as actuators, which canreceive power from the engine 116. Therefore, additional connectors canbe implemented to connect both hydraulic and electrical actuators to theengine 116.

FIG. 10 shows a modular three-point hitch assembly 200 mounted to therear interface mount 124. Similar to the rear arm assembly 197 shown inFIG. 9, the three-point hitch assembly 200 includes an interface portion201 for removably attaching the three-point hitch assembly 200 to therear interface mount 124 with bolts 202. The interface portion 201 caninclude one or more plate portions; in the illustrated embodiment, theinterface portion 201 includes an upper plate portion 201a and a lowerplate portion 201b (hidden from view in FIG. 10).

The three-point hitch assembly 200 includes an upper link 203 and a pairof lower links 206 having ends that are coupleable to various tools,including ground engaging tools such as a plow, a blade, an auger, acultivator, etc, as well as pallet forks, bale spears, rotary cutters,mowers, etc. (not shown). The three-point hitch assembly 200 providesmodularity to the utility vehicle 100. By modularity, it is meant thatthe three-point hitch assembly 200 provides a single package or unitthat can be installed on the utility vehicle 100 independently of othercomponents. The three-point hitch assembly 200 includes a pair of liftarms 209 fixed to a rock shaft 221 (hidden from view in FIG. 10).Movement of the lift arms 209 is effected through the use of a doubleacting hydraulic actuator 212. In other embodiments, other types ofmechanical or electrical double acting actuators that can receivehydraulic fluid or power from the engine are used to effect movement ofthe lift arms.

The double acting hydraulic actuator 212 provides the ability for theupper link 203 and the lower links 206 to lift. The double actinghydraulic actuator 212 also provides the ability to exert a downwardforce on the upper link 203 and the lower links 206. Such a downwardforce could be used to apply a downward pressure on various kinds ofground engaging tools. In one example, if the ground engaging tool is ablade, the double acting hydraulic actuator 212 can apply pressure onthe ground to scrape hard to remove ice. Likewise, if the groundengaging tool is an auger, the double acting hydraulic actuator 212 canapply pressure on the ground to dig a hole. In other embodiments,however, the double acting hydraulic actuator 212 can be replaced with asingle acting hydraulic actuator.

FIG. 11 shows a box 215 mounted on the rear interface mount 124. The box215 can also include a receiver hitch 218. The box 215 is supportedabove the rear wheel assembly 109 and behind the rear cover 121. The box215 is mounted to a top portion (hidden from view in FIG. 11) of therear interface mount 124, including the lateral mount portions 192. Asillustrated, the box 215 does not require the use of space on the rearinterface mount 124 that is otherwise needed for attaching other typesof work mechanisms, such as the front and side mount portions 183, 189.Therefore, the utility vehicle 100 can attach the box 215 on the rearinterface mount 124 in combination with a work mechanism mounted onother space on the rear interface mount 124. As illustrated, the rearinterface mount 124 can attach the towing hook 195 in combination withthe box 215 and receiver hitch 218.

Other configurations include attaching a rear arm assembly having a toolinterface plate in combination with the box 215 and attaching the threepoint hitch assembly 200 in combination with the box 215 (not shown).Although mounting the work mechanisms for these examples is permitted,some or all of the operability of the work mechanism may be impaired bythe box 215. For example, the box 215 may block lifting or pivoting ofthe work mechanism. Thus, although the work mechanism may not be fullyoperable in combination with the box 215, the user would be able toattach the box 215 without having to detach the work mechanism. In otherembodiments, the configuration of the box 215 can be adapted to permitoperation of the work mechanism (not shown). For example, the box 215may have a recessed portion to accommodate lifting or pivoting of thework mechanism.

The box 215 can be pivotally coupled to the rear interface mount 124 topermit tilting the box 215 for emptying the box 215. In some embodiments215, the box is manually tiltable. In other embodiments, tilting iseffected by hydraulic actuators or other mechanical or electricalactuators receiving power from the engine 116. Box tilting may beinhibited by the work mechanism mounted to the rear interface mount 124below the box 215.

FIG. 12 illustrates the three-point hitch assembly 200 according to anembodiment of the invention. The three-point hitch assembly 200 isadapted to mount to the rear interface mount 124 as previouslydiscussed. In other embodiments, the three-point hitch assembly 200 canbe mounted to other types of work or utility vehicles and not just forthe purposes of modularity as discussed above. The three-point hitchassembly 200 include the upper link 203, a pair of lower links 206, apair of lift arms 209, a rock shaft 221 and a hydraulic actuator 212. Inother embodiments, the three-point hitch assembly 200 is provided withother types of mechanical and electrical actuators which can receivehydraulic fluid or power from the engine 116 and which can be used inplace of the hydraulic actuator 212.

Each lift arm 209 is coupled to the rock shaft 221 with splines 224. Thethree-point hitch assembly 200 also includes a pair of leveling links227 that couple each lower link 206 to each lift arm 209, as well as anactuator arm 230. The actuator arm 230 is coupled to the hydraulicactuator 212 includes a receiving aperture 233 at the end opposite theend attached to the actuator 212. The rock shaft 221 is adapted forinsertion into the actuator arm 224 through the aperture 233. The end ofthe actuator arm 230 that includes the aperture 233 is free to rotateabout the rock shaft 221.

The actuator 212 of the three-point hitch assembly 200 can be adaptedfor providing tilting power to the box 215. The lift arms 209 aredetached from the leveling links 227 and pivoted about the rock shaft221 in a clockwise direction (i.e., upwards). The repositioned lift arms209 are coupled to the box 215 at pivot 236. When the actuator 212 isengaged, the lift arm 209 exert an upwardly directed force on the box215, raising the end of the box 215 and tilting the box 215.

As shown in FIGS. 13-14, the three-point hitch assembly 200 includes afloat mechanism 240. The float mechanism 240 includes a float block 243with first and second protrusions 246. The float block 243 is fixed tothe rock shaft 221 and rotates with the rock shaft 221. The floatmechanism 240 also includes a pair of open slots 249 in the actuator arm230. In the illustrated embodiment, the slots 249 are on opposite sidesof the rock shaft 221. Each protrusion 246 is received within one of theslots 249. The float mechanism 240 allows the pair of lower links 206 tomove in an upward direction without affecting the disposition of thehydraulic actuator 212. For example, if a tool attached to the ends ofthe lower links 206 were to hit a rock or other ground abnormality, asillustrated in FIG. 14, the lower links 206 will move upwardly asindicated by arrow 252 and therefore provide an upward force on the pairof lift arms 209 that is equivalent to a desire for lift arms 209 torotate in a clockwise direction as indicated by arrow 255. The lift arms209 are fixed to the rock shaft 221 and therefore cause the rock shaft221 to rotate. The rock shaft 221 is free to rotate relative to theactuator arm 230 within each slot 249. The rotation of the protrusions246 within the slots 249 allow the pair of lower links 206 to move in avertical distance without affecting the disposition of the hydraulicactuator 212 (note the position of the actuator 212, as indicated byarrow 258, is unchanged in FIGS. 13 and 14). Float mechanism 240 aidesin attaching a work tool to the three-point hitch assembly 200 as wellas implementing a float as required by most three-point hitch systemsfor safety reasons.

If the rotation of the protrusions 246 is sufficient (i.e. the lowerlinks 206 move a sufficient vertical distance) the protrusions 246bottom out in the slots 249, allowing force to be transferred from therock shaft 221 and actuator arm 230 to the hydraulic actuator 212.However, the work tool is unlikely to be vertically displaced to theextent necessary to rotate the protrusions 246 to the end of the slots249. The float mechanism 240 can therefore be considered a “free” floatmechanism.

In another embodiment, the three-point hitch assembly 200 includeslimited float mechanism in place of the free float mechanism describedabove. FIG. 15 illustrates a three-point hitch 200′ having a limitedfloat mechanism 240′. The three-point hitch assembly 200′ is generallysimilar to the three-point hitch assembly 200 shown in FIGS. 12-14, andlike parts are given like numbering in the ______'series.

The limited float mechanism 240′ is similar in many respects to the freefloat mechanism 240. However, the slots 249′ are on the rock shaft 221′and the protrusions 246′ are on the actuator arm 230′. In addition, theslots 249′ are smaller relative to the protrusions 246′. The protrusions246′ will tend to bottom out in the slots 249′ when the lower links 206′move a predetermined vertical distance.

The limited float mechanism 240′ facilitates exerting a downward forceon the work tool. This is accomplished by retracting the actuator 212′so as to rotate the actuator arm 230′ relative to the rock shaft 221′.As the slots 249′ bottom out against the protrusions 246′, the forceexerted by the actuator 212′ is transferred to the rock shaft 221′,which causes a downward force to be exerted on the work tool.

Thus, the invention provides, among other things, a multi-configurationutility vehicle. Various features and advantages of the invention areset forth in the following claims.

1. A three-point hitch assembly for a utility vehicle, the three-pointhitch assembly comprising: an upper link; a pair of lift arms; a pair oflower links coupled to the lift arms; a rock shaft connecting the liftarms; a hydraulic cylinder; an actuator arm coupling the hydrauliccylinder to the rock shaft for transferring a lifting force from thehydraulic cylinder to the rock shaft; and a float mechanism forinhibiting a transfer of force from the rock shaft to the hydrauliccylinder, the float mechanism including a float block fixed to the rockshaft, wherein the float mechanism includes a slot in one of the floatblock and the actuator arm and a protrusion in the other of the floatblock and the actuator arm, the protrusion being rotatable within theslot to permit rotation of the rock shaft relative to the actuator arm.2. The three-point hitch assembly of claim 1, wherein the protrusion ison the float block and the slot is in the actuator arm.
 3. Thethree-point hitch assembly of claim 1, wherein the protrusion is on theactuator arm and the slot is in the float block.
 4. The three-pointhitch assembly of claim 1, wherein the float mechanism includes a pairof opposed protrusions and a pair of opposed slots.
 5. The three-pointhitch assembly of claim 1, wherein the actuator arm includes a first endportion coupled to the hydraulic actuator and a second end portionhaving an aperture therethrough, the rock shaft being rotatably receivedwithin the aperture.
 6. The three-point hitch assembly of claim 1,wherein the float mechanism inhibits transfer of force from the rockshaft to the hydraulic actuator for a predetermined verticaldisplacement of the lower links and permits transfer of force from therock shaft to the hydraulic actuator beyond the predetermined verticaldisplacement of the lower links.
 7. The three-point hitch assembly ofclaim 6, wherein the protrusion bottoms out in the slot to permittransfer of force from the rock shaft to the hydraulic actuator beyondthe predetermined vertical displacement of the lower links.
 8. Thethree-point hitch assembly of claim 1, wherein the slot is open.
 9. Thethree-point hitch assembly of claim 1, further comprising an interfaceportion for removably attaching the three-point hitch assembly to aninterface mount of a utility vehicle.
 10. The three-point hitch assemblyof claim 6, wherein the interface portion includes apertures forreceiving bolts for mounting the three-point hitch assembly to theinterface mount.